Composition and method for influencing the growth of plants

ABSTRACT

The growth of plants is influenced, e.g., promoted or altered, by application thereto or to their habitat of a polymer or copolymer derived from an olefinically or diolefinically unsaturated compound or mixtures of such polymers and/or copolymers.

United States Patent [191 [451 May 27, 1975 Ehrig et al.

[ COMPOSITION AND METHOD FOR INFLUENCING THE GROWTH OF PLANTS [75]Inventors: Bodo Ehrig; Hermann Wolz, both of Leverkusen; ClausHentschel, Cologne, all of Germany [73] Assignee: BayerAktiengesellschaft,

Leverkusen, Germany [22] Filed: July 8, 1971 [21] Appl. No.: 160,962

[30] Foreign Application Priority Data UNITED STATES PATENTS 3,160,98512/1964 Ferguson et al. 71/85 3,307,932 3/1967 Guyot 7l/85 3,372,0203/1968 Regenstein, Jr. 7l/85 3,590,528 7/1971 Shepherd 71/79 3,592,9107/l97l Clark et al 71/85 3,707,807 l/l973 Graves 7l/85 3,755,064 8/1973Maierson 71/3 Primary Examiner-James 0. Thomas, Jr. Attorney, Agent, orFirmBurgess, Dinklage & Sprung [5 7] ABSTRACT The growth of plants isinfluenced, e.g., promoted or altered, by application thereto or totheir habitat of a polymer or copolymer derived from an olefinically ordiolefinically unsaturated compound or mixtures of such polymers and/orcopolymers.

13 Claims, No Drawings 1 COMPOSITION AND METHOD FOR INFLUENCING THEGROWTH or PLANTS The present invention relates to compositions forinfluencing, e.g. promoting. the growth of plants. Specifically, theinvention is directed to the use as plantgrowth-influencing agents ofcertain organic polymers.

Increasing the growth of tree nursery plants, ornamental plants,andespecially vegetables, is desirable because in a given period of timewith a given cultivated area a higher than-uSuaI yield can thereby beattained. A yield increase could also be achieved by promoting earlierblossoming in flower and ornamentalplant cultivation in the case of, forexample, slowgrowing and therefore particularly valuable plants (such as.bromeliads and orchids) grown in greenhouses. I Economically,increasing the growth as well as promotion of earlierblossoming andcropping would be exceptionally interesting and profitable.

It is already known that, for example in pineapple cultivation,promotion of earlier blossoming, and thus J an earlier, harvest, can beachieved by the action of acetylcne. Forthis purpose, either calciumcarbide is dissolved in water and the cisterns of the pineapple j plantare watered with this solution, or the cisterns are gassed directly withacetylene (see also J. L. Collins, "'The Pineapple Botany, Cultivationand Utilization Interscience Publishers, Inc., New York, 1960,

pp. 151 154). I This *method of gassing the cisterns of bromeliads isalso used in flower and ornamental-plant cultivation with theever-increasing success of bromelia plants on the, market.

Instead of acetylene, ethylene too has given good results see KOSMOS,Vol. 66, No. 5, pages 160 I63 No matter which of the known agents isused for blos- 50m influencing, one disadvantage is always to be bornein mind: the intended effect can occur only if the plant possesses acertain measure of readiness to blossom. Plant-s which are too young donot react at all to the treatment, others again form rudimentary blossomorgans so-that the treatment likewise remains without success. Thereexists, therefore, a need for a universal method for decreasing thegrowth time until blossoming and cropping which is free from theabovedescribeddisadvantages of the conventional methods.

It has now been found that a growth increase as well as a promotion ofearlier blossoming and cropping, es-

pecia'lly in useful and ornamental plants, can be I achieved by causingan organic polymeric material comprising a polymer or copolymer derivedfrom an olefinically or diolefinically unsaturated monomeric compound ora mixture of such polymers and/or copolymers to act on the plants ortheir habitat. The polymeric materials per se are known.

The present invention, therefore, provides a plantgrowth-influencingcomposition containing as active ingredient an, organic polymericmaterial as defined above, in admixture with a solid diluent or carrieror in composition containing as active ingredient an organic polymericmaterial as defined above in admixture with a solid or liquid diluent orcarrier.

It is decidedly surprising and was in no way to be foreseen that, by theaction of these organic polymers on useful plants and ornamental plantsor their habitat according to the process according to the invention, aconsiderable increase of plant growth and an economically profitableacceleration of blossoming and growth of such plants can be attained.

This new general process for growth increase as well as promotion ofearlier blossoming and cropping in plant cultivation permits not only asubstantial increase of yield but also gives, in addition, what inornamentalplant cultivation is especially desirable, a brilliance offlower not to be attained according to other cultivation methods.

The conventional organic polymeric materials which can be used accordingto the invention are defined generally above. Preferred are thosehomopolymers or copolymers which can be prepared by polymerization fromthe following monomers:

a. esters of acrylic acid or-methacrylic acid with l-18 carbon atoms,preferably l-8 carbon atoms, in the alcohol residue, for example methylacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, ethylmethacrylate, butyl methacrylate as well as their mixtures;

b. vinyl aromatics, for example styrene, halostyrenes or styrenessubstituted by alkyl groups (the alkyl group of the vinyl groupcontaining preferably 1 or 2 carbon atoms), such as methylstyrene,p-methylstyrene, o-isopropylstyrene and p-chlorostyrene;

c. vinyl esters of organic carboxylic acids which contain 2-16 carbonatoms, for example vinyl propionate, vinyl butyrate, vinyl benzoate,Versatic acid vinyl ester and, especially, vinyl acetate;

d. diene hydrocarbons. such as butadiene, isoprene, piperylene,1,3-dimethylbutadiene, hexadi-l,3-ene, 4- methylpentadi-l,3-ene andchloroprene, preferably conjugated diene hydrocarbons with 4-6 carbonatoms;

e. a, B-unsaturated nitriles of carboxylic acids with 3-5 carbon atoms,for example acrylonitrile or methacrylonitrile;

f. vinyl halides, for example vinylidene chloride, vinyl bromide,vinylidene bromide, vinyl fluoride and, especially, vinyl chloride;

g. mono-olefins with preferably 2-10 carbon atoms, such as ethylene,propylene, butylene, hex-l-ene, octl-ene or iso-octene.

Preferably, those polymers are used which do not harden or cross-linkunder the influence of atmospheric oxygen.

Preparation of the polymers to be used according to the invention fromthe monomers in known. It can be effected, for example, by solventpolymerization, emulsion polymerization, bead polymerization, suspensionpolymerization or precipitation polymerization (see Methoden derorganischen Chemie, Houben-Weyl, Vol. 14/1 (1961), pages 131-503).

In the following, particulars are given for the preparation, accordingto various polymerization processes, of organic polymers which can beused according to the invention.

If the polymers are prepared in solution by radical polymerization, thenature of the solvent is determined solely by the monomers used. In thecase of anionic or cationic polymerization, as well as in the case ofpoly- 3 rnerization with Ziegler-Nana catalysts, the customary nonpolarsolvents, for example hydrocarbons, such as benzine, benzene or toluene.are used,

As polymerization catalysts, inorganic per" compounds, such as potassiumor ammonium persulfate, hydrogen peroxide and percarbonates, such assodium percarbonate, organic peroxide compounds, for example acylperoxides, such as benzoyl peroxide, alkyl hydroperoxides, such astert.-butyl hydroperoxide, cumene hydroperoxide and p-methanehydroperoxide. dialkyl peroxides, such as di-tert.-butyl peroxide,peroxy esters, such as perbenzoic acid tert.-butyl ester, and azocompounds, for example azoisobutyric acid nitrile, are suitable.Advantageously, the inorganic or organic per" compounds are used incombination with reducing agents in a known manner. Suitable reducingagents are, for example, sodium pyrosulfite or bisulfite, sodiumformaldehyde sulfoxylate, triethanolamine and tetra-ethylenepentamine.

The polymerization in solution can be carried out with, besidesperoxides:

a, anionic catalysts, such as lithium butyl, sodium phenyl or diphenyldipotassium silane;

b. cationic catalysts, for example boron(lll) fluoride; and

c. complex catalysts of the Ziegler-Natta type, such as nickelacetonylacetate or aluminium sesquichloride.

The amount of catalyst lies within the limits usually appropriate inpolymerization of the type, for example between 0.01 and 5 per cent byweight, with reference to the total amount of monomer.

In order to influence the molecular weight, the usual regulators, suchas long-chain alkylmercaptans, diisopropyl xanthates, nitro compounds ororganic halogen compounds, can be used in the polymerization.

lf preparation of the polymers to be used according to the inventiontakes place in an emulsion, the emulsifier may be an anionic nonionic orcationic emulsifiers or a combination of such emulsifiers.

Examples of cationic emulsifiers are salts of quaternary ammonium orpyridinium compounds.

As non-ionic emulsifying agents, the known reaction products of ethyleneoxide with long-chain fatty alcohols or phenols are suitable; generally,reaction products of more than moles ethylene oxide per mole of fattyalcohol or phenol are used.

The total amount of the above-mentioned emulsifiers can be between 0.5and 20, preferably between 2 and 10, per cent by weight, with referenceto the toal amount of monomer.

If preparation of the polymers takes place by bead polymerization,natural or synthetic high-molecularweight substances are used asprotective colloids. There may be mentioned for example: agar-agar,methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol or alkalimetal salts of polyacrylic acid.

The polymerization temperatures are governed by the types of monomerused and the activation systems, and lie between 0 and 150C, preferablybetween 40 and 90C.

The organic polymers which can be used according to the inventionaccelerate strongly the growth of higher plants and can therefore beused as agents for increasing growth as well as for promoting earlierblossoming and cropping in useful and ornamental plant cultivation. Theuseful plants include for example the cultivated plants:

Compositae, such as lettuce (Lactuca sativa, especially var. capiram),leaf lettuce (Lactuca sativa, var. crispa); Cucurbitaceae, such ascucumber (Cucumis sativus), melon (Cucumis melo), pumpkin (Cucurbitapepo); Cruciferae, such as radish (Raphanus, var. sativus); Liliaceae,such as chive (Allium schoenoprasum); Umbelliferae, such as celery(Apium, var. rapaceum), parsley (Pelroselinum crispum); Orchidaceae,such as kohlrabi (Brassica oleracea gongvloides); Solaneceae, such astomato, (Solarium lyropersicum); Chenopodiaceae, such as spinach(Spinacia oleracea); Leguminosae, such as bean (Phasealus vulgaris), pea(Pisum salivum); Gramineae, such as sugar cane (Saccharum 0fficinarum),maize (Zea), rice (Oryza sativa); Solanaceae, such as tobacco (Nicotianatabacum Malvaceae, such as cotton (Gassypium peruvianum); Rosaceae, suchas strawberry (Frageria ananassa); cotoneaster (Cotoneaster dammei);further, woody plants, for example Caprifoliaceae, such as honeysuckle(Lonicera pileata), snowberry (Symphoricarpos racemosus); Taxaceae, suchas yew (Taxus); Ericaceae, such as erica (Erica); as well as varioussmall woody plants, for example Sarcococca, Forsythia, Prunus, Theornamental plants include for example the following: Araliaceae, such asivy (Hedera helix); Begoniaceae, such as begonia (Begoniasemperflorens); Onagraceae, such as fuchsia (Fuchsia); Geraniaceae, suchas pelargonium (Pelargonium zonale); Moraceae, such as rubber plant(Ficus); Gesneriaceae, such as columnea (Columnea microphylla);Malvaceae, such as China rose (Hibiscus r0sasinensis); Liliaceae, suchas tulip (Tulipa gesneriana), hyacinth (Hyacinthus orientalis);Iridaceae, such as gladiolus (Gladiolus); Polypodiaceae, such as fern(Nephrolepis exaltata), maidenhair fern (Adiantum), spleenwort(Asplenium vidus), stag-horn fern (Platycerium alcicorne); Compositae,such as chrysanthemum (Chrysanthemum indicum), aster (Callistephaschinensis), sunflower (Helianthus), dahlia (Dahlia variabilis), ageratum(Ageratam houstonianum); Euphorbiaceae, such as croton (Codiaeumvariegatum), spurge (Eup/zorbia); Araceae, such as flamingo flower(Anrhurium) or Rhaphidophora aurea; further, philodendron(Philodendron), dieffenbachia (Dieffenbachia) as well as various bed,balcony and group plants, for example salvias, petunias, calceolarias.

The polymeric compounds are especially suitable for causing inCompositae such as lettuce, in Umbelliferae such as parsley and inBromeliaceae, such as pineapple, an increase of growth or a promotion ofearlier blossoming and cropping. The growth increase manifests itself inhead lettuce not in shorting but in an improved formualtion of thelettuce heads.

The polymeric compounds to be used according to the present inventionare used preferably in the form of their aqueous dispersions. They may,however, be applied as such or be converted into the usual formulations,such as solutions, emulsions, suspensions, oils, powders, pastes andgranulates. These may be produced in known manner, for example by mixingthe active compounds with extenders, that is, liquid or solid diluentsor carriers, optionally with the use of surfaceactive agents, that is,emulsifying agents and/or dispersing agents. In the case of the use ofwater as an extender, organic solvents can, for example, also be used asauxiliary solvents.

As liquid diluents or carriers, there are preferably used aromatichydrocarbons, such as xylenes or benzene, chlorinated aromatichydrocarbons, such as chlorobenzenes, paraffins, such as mineral oilfractions, alcohols, such as methanol or butanol, or strongly polarsolvents, such as dimethyl formamide or dimethyl sulfoxide, as well aswater.

As solid diluents or carriers, there are preferably used ground naturalminerals, such as kaolins, clays, talc or chalk, or ground syntheticminerals, such as highly-dispersed silicic acid or silicates.

Preferred examples of emulsifying agents include non-ionic and anionicemulsifiers, such as polyoxyethylene-fatty acid esters, polyoxyethylene-fatty alcohol ethers, for example alkylarylpolyglycol ethers,alkyl sulfonates and aryl sulfonates; and preferred examples ofdispersing agents include lignin, sulfite waste liquors and methylcellulose.

The polymers may in these applications forms also be present inadmixture with other active compounds custom ary in plant cultivation,for example selective herbicides, fungicides and/or insecticides. Theformulations contain, in general, from 0.1 to 99, preferably from 0.5

to 95, per cent by weight of the active polymeric compound.

The polymers may be introduced into the habitat of the plant by any ofthe methods usual in agriculture and horticulture, such as by watering,dusting, spraying, squirting, scattering and, where appropriate, also bysoil injections or working into the soil (plant substrate), for exampleby ploughing or digging or by mixture with artificial substrates. Byhabitat of the plant are meant both natural and artificial substrates,including soilless cultures, as well as flooded cultures, such as areusual in the cultivation of rice, for example paddy rice.

The polymeric compounds can be mixed with the plant substrate bothbefore sowing and after between sowing and emergence of the plants; thepolymeric compounds may, however, also by applied after the emergence ofthe plants, for example by watering or spraying.

The amount used of the organic polymeric material may vary within fairlywide ranges: it depends essentially on the nature and extent of thedesired effects. In general, the amounts applied are from 10 to 200 g.polymer/square meter, preferably from 50 to lg/square meter.

When aqueous dispersions are used, the content of the organic polymermaterial is, in general, from 50 to 750g/liter.

lf pot plants are treated using the process according to the invention,the amount applied is, in general,

about 1. g. with a pot diameter of, on average, 6' cm.

The present invention is illustrated in and by the following Examples.

EXAMPLE A Head lettuce test (growth increase) Polybutadienedispersion/loamy soil and peat soil/- transplanting box.

As the preparation of active compound, an aqueous polybutadienedispersion with a content of polybutadiene of 30 per cent by weight wasused which was obtained in a known manner by emulsion polymerization ofbutadiene (see,for example, Methoden der Organischen Chemie,Houben-Weyl, Vol. 14/1 (1961 pages 131-503).

Different amounts of this polybutadiene dispersion were by thoroughmixing worked into in each case equal parts, by volume of soil whichwere in transplanting boxes equal to one other in size. In one caseloamy soil (A) was used and in the other case peat soil (B) was used,the peat soil containing, from the outset, as standard fertilizer 2.5 kgNPK fertilizer (with 12 percent nitrogen content, 12 percent phosphoruspentoxide content and 20 percent potassium oxide content) and 3 kgcalcium carbonate per cubic meter of peat.

Into the differently composed substrates so obtained there weretransplanted the same number of head lettuce plants per transplantingbox, and cultivation was effected for 32 days. At the same time, forcomparison, the same number of control plants of head lettuce wascultivated in a further transplanting box in each case, the substratebeing loamy soil or peat soil (of the composition stated above) nottreated with polybutadiene dispersion, but otherwise under the sameconditions.

For evaluation, after 32 days the average weight per head lettuce plantwas determined, once in the fresh state and once in the dried state. Theindividual lettuce plants were cut off immediately above the soil,weighed, then dried and again weighed. The drying of the test plants waseffected at 80C. in a vacuum of mm Hg for 60 hours.

From the following Table A (i) can be seen the amounts used ofpolybutadiene dispersion per unit volume of loamy soil (stated in mldispersion/1000 cc loamy soil), the value 0 referring to the controlexperiment, and as results the measured average weights per test plant(in g) in the fresh and in the dried state:

Table A(i) (loamy soil) Amount of polybutadiene Average weight per testdispersion (30% strength) plant (in g) per 1000 cc loamy soil (in ml)fresh dried 4O From the following Table A(ii) can be seen the testconditions and results with the use of peat soil:

Table A(ii) (peat soil) Amount of polybutadiene Average weight per testHead lettuce test (head formation) Polybutadiene dispersion/loamy soiland peat soil/- hotbed.

To several hotbeds which were filled with, in each case, 100,000 cc(=10O liters) of loamy soil or peat soil (as in Example A) there wereapplied by uniform watering by means of a watering can such amounts ofan aqueous 30 percent strength polybutadiene dispersion (as in ExampleA) that the same amounts per 1000 cc of loamy soil or peat soil arepresent as in the transplanting boxes according to Table A(i) or A(ii).

Into the so-treated hotbeds there were transplanted. for observation ofhead formation. in each case 12 lettuce plants which had beforehand beengrown for 60 days in transplanting boxes with a substrate of the samecomposition. The plants are cultivated for a further 30 days untilevaluation.

For comparison, in a control experiment for loamy soil and peat soil.respectively, in each case 12 untreated lettuce plants were cultivatedfor a total of. in each case, 90 days in hotbeds to which nopolybutadiene dispersion had been applied.

The evaluation took place in the same way as stated In Example A.

Analogously with Table A(i) there can be seen from the following TableB(i) the test conditions and results with the use of loamy soil:

Table B(i) [loamy soil) Amount of polybutadiene dispersion (307:strength) per I000 cc loamy soil (in ml) Average weight per lettuce head(in g) dried From the following Table B(ii) can be seen thecharacteristic test conditions and results with the use of peat soil:

Table B(ii) (peat soil) Amount of polybutadiene Average weight perParsley test (growth increase) Polybutadiene dispersion/peatsoil/transplanting box.

Analogously with Example A. parsley plants were cultivated in peat soilwhich had been treated with different amounts of aqueous 30 percentstrength polybutadiene dispersion, transplanted and cultivated for 21 55days.

The evaluation took place as stated in Example A. Analogously with TableA(ii), there can be seen from the following Table C the test conditionsand results:

5 Table C (peat soil) Amount of polybutadiene dispersion (30% strength)Average weight per plant Parsley test (growth increase) Polybutadieneoil/peat soil/transplanting box.

As the preparation of active compound, a I00 per- 20 cent strengthpolybutadiene oil was used which was prepared in a known manner (seeExample I of Belgian Patent Specification No. 742,971).

The test method and the evaluation method are the same as described inExample A. The test plants were 25 cultivated for 21 days. Peat soilserved as the substrate.

Analogously with Table A(ii), there can be seen from the following TableD the test conditions and the results:

Table D (peat soil) Amount of 1007: strength Average weight per plantpolybutadiene oil per (i I000 cc peat soil (in ml) fresh dried EXAMPLE ELeaf lettuce test (growth increase) lOO percent polybutadiene oil/loamysoil and peat soil/transplanting box.

Analogously with Example D, I00 percent polybutadiene oil was used asthe active compound.

The test method was the same as described in Example A. The evaluationtook place, with a total duration of the test of 35 days, on the lst,7th, 14th, 21st, 28th and 35th day, by determining the values for theNumber of leaves/length of leaves (in cm), for test plants and controlplants.

From the following Table E(i), there can be seen the test conditions andthe results with the use of loamy soil:

Table B(i) Amount of I00% (loamy soil) Number of leaves/length of leaves(in cm) polybutadiene oil per I000 cc Evaluation on loamy soil lst 7th14th 21st 28th 35th (in ml) day day day day day day 12.5 2/3 4/4 5/5.56/6-7 89/7.75 lO-I l/78 Table E(i) Continued (loamy soil) Amount of 100%Number of leaves/length of leaves (in cm) E(ii), there can be seen thelts with the use of peat soil.

From the following'Table test conditions and the resu same as describedin Example A. The evaluation took place (analogously with Example E),

with a total dura- Table E(ii) (peat soil) Amount of l% Number ofleaves/length of leaves (in cm) polybutadiene oil per i000 cc Evaluationon peat soil 1st 7th l4th 21st 28th 35th (in ml) day day day day day day0 2/2 2/ 1-4 4/2.5-4 5/33.5 6/4-5 6-8/4-6 2.5 2/ 1-2 2/3 4/3-4 6/4-56-7l4.5 /5-6 12.5 2/2 2-4/3.5 4-5/'3.S 6/4-6 8-9/5-6 10/7-9 2/2.52-4l3.5-4 4-5/3-4 6/5.5-6 9/6. 5 l0/78.5 75- 2/2 T 2/3 4/3-4 5/4-5.5 8/5l0/66.5

EXAMPLE F tion of the test of days, on the 1st, 7th, 14th, 21st,

Leaf lettuce test (growth increase) Polybutadiene dispersion/loamy soiland peat soil/- transplanting box.

28th and 35th day, likewise by determination of the values for theNumber of leaves/length of leaves (in cm)", for test and control plants.

From the following Table F(i) there can be seen the test conditions andthe results with the use of loamy As the preparation of active compound,an aqueous soil:

Table F(i) (loamy soil) Amount of poly- Number of leaves/length ofleaves (in cm) butadiene dispersion (30% Evaluation on strength) per1000 cc loamy 7th 14th 21st 28th 35th soil day day day day day day (inml) 0 2/2 2/2.5-3 413.5-4 415.5 6/5.5 9-10/6-7 l0 2/2.5 3/3.54 4/5 6/79/7.58.5 1218-9 212-25 2/3 414.5 6/7-8 9/8-9 12/1 l 1/1 2/1 2/l.53-4/2-3 5/3-4 8/6-7 300 110.5 110.5

utadiene dispersion according to Example A was used.

Amount of polybutadiene dispersion (30% strength) per i000 cc 'peat lstsoil day (in ml) From the following Table F(ii) there can be seen thetest conditions and the results with the use of peat soil:

Table F(i) (peat soil) Number of leaves/length of leaves (in cm) TableF(i) Continued (peat soil) Amount of polybutadiene dis- Number ofleaves/length of leaves (in cm) persion (30% Evaluation on strength) per1000 cc peat lst 7th 14th 21st 28th 35th soil day day day day day day tin ml) EXAMPLE G mer which was obtained from 60 percent butadiene, 34

Radish test percent styrene and 6 percent methacrylic acid.

.Polybutadiene dispersion/peat soil/transplanting box.

As the preparation of active compound, an aqueous 30 percent strengthpolybutadiene dispersion according to Example A was used.

The test plants were grown in two different substrates: (a) in peatculture substrate (type TKE I), that was young peat to which a mineralfertiliser in a form as fine as dust had been added so that the contentof nitrogen was 180, phosphoric acid 180, potassium hydroxide 225, lime1350 and magnesium 180 mg. per 1000 cc of substrate; and (b) in peatsoil (as described in Example A) to which ml of an aqueous percentstrength polybutadiene dispersion per 1000 cc of substrate were admixed.

The two sorts of freshly germinated radish plants were then transplantedanalogously with Example A into peat soil which again contained variousamounts of the same polybutadiene dispersion.

After a culture duration of 22 days, for evaluation analogously withExample E and F the values for the Number of leaves/length of leaves (incm) were determined separately for the test plants grown according to(a) and according to (b).

From the following Table G can be seen the test conditions and theresults:

Table G (peat soil) Number of leaves/length of leaves (in cm) Amount ofpolybutadiene dispersion (307: strength) per I000 cc peat soilBromeliads test (growth increase and acceleration) Copolymers/substratefor Epiphytes (air plants")/pot culture As preparation of activecompound, three different copolymers were used which can be obtained ina known manner by emulsion copolymerization.

Copolymer A:

58 percent strength aqueous dispersion of a copoly- Copolymer B:

percent strength aqueous dispersion of a copolymer which was obtainedfrom 57 percent butadiene, 5 percent styrene and 38 percentacrylonitrile.

Copolymer C:

45 percent strength aqueous dispersion of a copolymer which was obtainedfrom 58 percent nbutylacrylate, 2 percent acrylamide, 3 percentmethacrylic acid amide N-methylolmethyl ether, 35 percent styrene and 2percent acrylic acid.

Different amounts of the three copolymers A, B and C were worked into asoil mixture consisting of steamed compost soil, leaf mould (see 1.Keller and H. K. Mohring, Die D't'mgung in der gartnerischen Praxis,Verlag Paul Parey in Berlin and Hamburg, 1966, pages ll, 12 and and sandin the ratio 2:1:1. With the use of this substrate, the two bromeliadsNidu- [aria Meyendorffii and Neoregelia Carolinae Tricolor were potted,and cultivated for 4 months.

After this time, the growth and the general condition of the plant wasassessed with regard to (1) rooting (2) shoots (sprouts) and (3)colouring.

For evaluation, 5 ratings were used which have the following meaning:

Very good at least 3 sprouts, strong roots, un-

usual colour brilliance;

good l sprout, very beautiful colour production;

normal no discernible deviations or noteworthy differences from thecontrol plants;

moderate minor damage;

poor growth impaired, greater damage, (falloffs), discolored leaf-tips.

From the following Table H can be seen the characteristic testconditions and the individual evaluations:

Table H Amount of copolymer Evaluation of the effect on the It will beunderstood that the specification and examples are illustrative but notlimitative of the present invention and that other embodiments withinthe spirit and scope of the invention will suggest themselves to thoseskilled in the art.

What is claimed is:

1. Method of increasing, stimulating and promoting the growth of plants.which comprises applying to the soil of plants a dispersion comprisinga dispersant, and, as an active ingredient, from 50 to 750 grams of anor ganic polymeric material selected from the group consisting ofpolybutadiene, a copolymer of butadiene, styrene and acrylic acid, acoplymer of n-butylacrylate, acrylamide, styrene and acrylic acid. acopolymer of butadiene, styrene and metharcylic acid. copolymer ofbutadiene, stryene and acrylonitrile and a copolymer of n-butylacrylate,acyrlamide, metharcylic acid amide N-methylolmethyl ether, styrene andacrylic acid.

2. Method as claimed in claim 1 wherein said polymeric material ispolybutadiene.

3. Method as claimed in claim 1 wherein said polymeric material is acopolymer of butadiene, styrene and acrylic acid.

4. Method as claimed in claim 1 wherein said polymeric material is acopolymer of n-butylacrylate, acrylamide, styrene and acrylic acid.

5. Method as claimed in claim 1 wherein said polymeric material isapplied to the soil in an amount between 10 and 20 grams of polymer persquare meter of soil.

6. A method according to claim 5 wherein the plant is lettuce and thepolymeric material is polybutadiene.

7. A method according to claim 5 wherein the plant is parsley and thepolymeric material is polybutadiene.

8. A method according to claim 6 wherein the lettuce is head lettuce.

9. A method according to claim 6 wherein the lettuce is leaf lettuce.

10. A method according to claim 5 wherein the plant is radish and thepolymeric is polybutadiene.

11. A method according to claim 5 wherein the plant is an Epiphytes andthe polymeric material is a copolymer of butadiene, styrene andmethacrylic acid.

12. A method according to claim 5 wherein the plant is an Epiphytes andthe polymeric material is a copolymer of butadiene, styrene andacrylonitrile.

13. A method according to claim 5 wherein the plant is an Epiphytes andthe polymeric material is a copolymer of n-butylacrylate, acrylamide,methacrylic acid amide N-methylolmethyl ether, styrene and acrylic acid.

1. METHOD OF INCREASING, STIMULATING AND PROMOTING THE GROWTH OF PLANTSWHICH COMPRISES APPLYING TO THE SOIL OF PLANTS A DISPERSION COMPRISING ADISPERSANT, AND, AS AN ACTIVE INGREDIENT, FROM 50 TO 750 GRAMS OF ANORGANIC POLYMERIC MATERIAL SELECTED FROM THE GROUP CONSISTING OFPOLYBUTADIENE, A COPOLYMER OF BUTADIENE, STYRENE AND ACRYLIC ACID, ACOPOLYMER OF NBUTYLACRYLATE, ACRLAMIDE, STYRENE AND ACRYLIC ACID, ACOPOLYMER OF BUTADIENE, STYRENE AND METHARCYLIC ACID, COPOLYMER OFBUTADIENE, STYRENE AND ACRYLONITRILE AND A COPOLYMER OF NBUTYLACRYLATE,ACYRLAMIDE, METHACRCYLIC ACID AMIDE NMETHYLOLMETHYL ETHER, STYRENE ANDACRYLIC ACID.
 2. Method as claimed in claim 1 wherein said polymericmaterial is polybutadiene.
 3. Method as claimed in claim 1 wherein saidpolymeric material is a copolymer of butadiene, styrene and acrylicacid.
 4. Method as claimed in claim 1 wherein said polymeric material isa copolymer of n-butylacrylate, acrylamide, styrene and acrylic acid. 5.Method as claimed in claim 1 wherein said polymeric material is appliedto the soil in an amount between 10 and 20 grams of polymer per squaremeter of soil.
 6. A method according to claim 5 wherein the plant islettuce and the polymeric material is polybutadiene.
 7. A methodaccording to claim 5 wherein the plant is parsley and the polymericmaterial is polybutadiene.
 8. A method according to claim 6 wherein thelettuce is hEad lettuce.
 9. A method according to claim 6 wherein thelettuce is leaf lettuce.
 10. A method according to claim 5 wherein theplant is radish and the polymeric is polybutadiene.
 11. A methodaccording to claim 5 wherein the plant is an Epiphytes and the polymericmaterial is a copolymer of butadiene, styrene and methacrylic acid. 12.A method according to claim 5 wherein the plant is an Epiphytes and thepolymeric material is a copolymer of butadiene, styrene andacrylonitrile.
 13. A method according to claim 5 wherein the plant is anEpiphytes and the polymeric material is a copolymer of n-butylacrylate,acrylamide, methacrylic acid amide N-methylolmethyl ether, styrene andacrylic acid.